Revolver — The Beatles (1966)

Revolver, released in August 1966, remains the most audacious studio experiment of its era, featuring backward guitar tracks, string quartets, and tape loops that no engineer had attempted before. It is consistently ranked among the two or three greatest albums ever recorded, and it is cheaper than the typical rival in terms of production cost yet yielded a sonic range—from Motown-influenced pop to avant-garde exploration—that simply outperforms #3 Pet Sounds in sheer diversity. Its impact, 3 million UK sales, proved the Beatles could do anything.